Created by the eponymous Project: Mothervine, Mothervine represents yet another attempt to weaponize genetic mutation in the Ultimate Universe. A refinement of the original creation of mutants, it is a serum intended to be injected into pregnant women, causing them to give birth to mutant children. Jimmy Hudson, the son of Wolvernine and Magda, is the only known mutant alive today to have been affected by this serum during gestation (and his mutant blood is the sole remaining source of the drug).
In most cases, where neither parent is a mutant, the mutations caused by Mothervine will tend to remain latent unless activated by some trauma, or by the hearing of a passphrase that is somehow coded into the drug, and will cause immediate and uncontrollable activation of the mutation when heard. The mechanism of this encoding is unclear, nor is it known whether it transcends language.